Question
Physics Question on Ray optics and optical instruments
A given ray of light suffers minimum deviation in an equilateral prism P. Additional prisms Q and R of identical shape and of the same material as P are now added as shown in the figure. The ray will suffer
A
greater deviation
B
no deviation
C
same deviation as before
D
total internal reflection
Answer
same deviation as before
Explanation
Solution
Figure (a) is part of an equilateral prism of figure (b) as
shown in figure which is a magnified image of figure (c).
Therefore, the ray will suffer the same deviation in figure (a)
and figure (c).
NOTE Questions are often asked based on part of a prism. For
example, section shown in figure (a) is part of a prism shown in
figure (c).